THEIA II navigation watch with offline maps

Compare the same mode on all GPS watches.

Makers quote battery life per mode, so compare GPS mode with GPS mode across all the watches you look at. Multi-band GPS uses more battery power than standard GPS tracking, so it gives shorter battery life. An always-on display uses more again: Garmin rates the Garmin Fenix 8 AMOLED 47 mm at up to 47 h in GPS mode and up to 37 h with the display always on.

Battery saving modes give improved battery life by lowering GPS accuracy, and solar charging adds hours in bright light. All figures are the makers’ own best cases. When testing GPS watches yourself, expect fewer hours in the cold and with the screen at full brightness, THEIA II included.

For trips of several weeks.

Of the GPS watches compared here, the Garmin Enduro 3 has the best battery life. Garmin rates it at up to 320 h with GPS and solar charging, measured in 50,000 lux, and up to 120 h in multi-band mode. It has sapphire crystal, a built-in flashlight and TopoActive topo maps preloaded.

For trips of several weeks away from power, the Garmin Enduro 3 is the better choice; THEIA II is rated 15 h with GPS.

Two more expedition GPS watches.

Suunto rates the Suunto Vertical 2 at up to 250 h in Tour mode, with lower GPS accuracy, and up to 65 h in multi-band mode. It has an integrated flashlight, and Suunto offers free maps for it.

COROS rates the COROS VERTIX 2S at 118 h with GPS. It has a sapphire crystal screen. The Suunto Vertical 2 and the COROS VERTIX 2S both give long battery life on routes where you cannot charge.

Garmin’s outdoor range.

Garmin rates the Garmin Fenix 8 AMOLED 47 mm at up to 16 days in smartwatch mode, up to 47 h with GPS and up to 35 h in multi-band mode.

Garmin rates the Garmin Instinct 3 AMOLED 50 mm at up to 24 days in smartwatch mode, up to 40 h with GPS and up to 30 h in multi-band mode. Garmin makes outdoor watches and sports watches for most sports.

For iPhone users.

Apple rates the Apple Watch Ultra 4 at up to 50 h in normal use, up to 84 h in Low Power Mode and up to 18 h of workout tracking. It takes phone calls, runs third party apps and has music storage.

It suits iPhone and Apple Watch users who want one device for phone calls and the outdoors, on day trips. Workout tracking gives the Apple Watch Ultra 4 shorter battery life than the expedition GPS watches; for long battery life over several days, the expedition GPS watches above last longer.

If pace and a training plan come first.

For trail runners who follow a training plan, running watches such as the Garmin Forerunner, and other sports watches built for trail running, offer training tools such as training load and recovery.

THEIA II has a running mode and fitness tracking, and syncs to Strava. If your training history is in the Polar Flow app or Garmin Connect, check how you would move it before you switch.

Topo maps, GNSS, two bands.

GPS watches use GNSS, the satellite systems that include GPS. Dual-frequency GPS listens on two bands and gives a cleaner track in valleys and forest. THEIA II, the Garmin Fenix 8, the Garmin Instinct 3, the Garmin Enduro 3 and the Suunto Vertical 2 all offer dual-frequency or multi-band GPS.

Maps differ more. The Garmin Enduro 3 ships with TopoActive topo maps preloaded, and Suunto offers free maps; THEIA II stores the maps you load from your computer, in 4 GB. If you need detailed topo maps with contour lines, check what each maker offers for your region.

Day trips and everyday wear.

THEIA II costs CHF 369 or CHF 469. It has maps in 4 GB, dual-frequency GPS, return to start, a barometric altimeter and a compass in 58 g, with glass you replace yourself.

It suits day hikes, ski tours, mountaineering days, sailing and everyday wear. It does not suit multi-day trips without charging. It has no solar charging and no flashlight; if you need either, choose one of the other watches above. If you only walk marked trails, an affordable watch without maps may be enough.

Count the hours you spend with GPS on.

Battery life is the figure that varies most between the best GPS watches. Most GPS watches quote three figures: smartwatch use, standard GPS and multi-band tracking. On GPS watches, multi-band GPS gives shorter battery life; battery saving modes give longer battery life with less precise GPS.

For a day out, count the hours you walk with GPS tracking on: THEIA II is rated 15 h with GPS on, and Garmin rates the Garmin Fenix 8 AMOLED 47 mm at up to 47 h. For long battery life over several days without a charger, look at GPS watches with solar charging: Garmin rates the Garmin Enduro 3 at up to 320 h with GPS and solar charging, and COROS rates the COROS VERTIX 2S at 118 h. For long-lasting battery life over several weeks, solar charging is the feature to look for.

Valleys, forest and cliffs.

GPS watches calculate your position from the signals of several GNSS satellites. How accurate the track is depends on the receiver and on how much open sky GPS watches can see. Dual-frequency GPS listens on two signal bands and gives more accurate tracking where signals bounce, at the cost of some battery life. Among the best GPS watches compared here, THEIA II, the Garmin Fenix 8, the Garmin Instinct 3, the Garmin Enduro 3 and the Suunto Vertical 2 all offer it. On open ground, single-band GPS watches use less battery life.

Offline maps and topo maps.

If you leave marked trails, maps matter more than any other feature of GPS watches. Check whether the maps work offline, whether they show contour lines, and how you load them. Maps and a bright screen also cost battery life on long days. Among the best GPS watches for maps, the Garmin Enduro 3 ships with TopoActive topo maps. Polar preloads maps of Europe and North America on the Polar Grit X2 Pro and lets you add more through Polar Flow. Suunto watches such as the Suunto Vertical 2 take free maps for offline use, with 32 GB of map storage. THEIA II stores up to 4 GB of maps you load from your computer, and you plan routes on OpenStreetMap in its mapping app.

Altimeter, barometer, compass, heart rate.

For the mountains, look for ABC sensors: altimeter, barometer and compass. A barometer that follows the pressure drop gives a storm warning. A digital compass shows your heading even when you stand still, which GPS watches without a compass cannot. Sensors that measure all day, such as heart rate and blood oxygen, also cost battery life. Heart rate and a pulse oximeter matter for training, fitness tracking and sleep tracking. Check whether the GPS watches you compare have a barometric altimeter or only a GPS altitude. THEIA II has all of these.

Glass, bezel, water resistance.

On GPS watches for the mountains, look for water resistance, a screen you can read in sun, and glass and a bezel that take knocks. The best GPS watches for expeditions often use sapphire crystal and a steel or titanium bezel: the Suunto Vertical 2 and the Polar Grit X2 Pro have a stainless steel bezel and sapphire glass, the COROS VERTIX 2S has a sapphire crystal screen, and Garmin sells the Garmin Fenix 8 in sapphire editions. Amazfit says the Amazfit T-Rex 2 passed 15 military-standard MIL-STD-810G tests. THEIA II uses W-Glass over Gorilla glass, which you replace yourself when it scratches. It is rated 10 ATM, so it goes in the rain and spray with the rest of your outdoor gear.

Phone calls, music, apps.

Some GPS watches take phone calls, store music and run third party apps; among the best GPS watches, the Apple Watch Ultra 4 does all three, and Apple rates it at up to 18 hours of outdoor workout tracking. THEIA II shows message notifications, syncs to Strava and gives you even the ability to find your phone from the wrist. If phone calls and music storage on the wrist matter to you, check each of the GPS watches before you buy: phone calls, music and an always-on screen all cost battery life.

Training tools and recovery.

Trail runners who follow a plan need training tools and advanced features: training load, recovery and performance tracking. If you compare the best GPS watches for trail running races, look at running watches such as the Garmin Forerunner, and at other sports watches built for trail running. Garmin sells the Garmin Forerunner series for running. THEIA II has a running mode; for training plans, a Garmin Forerunner is the better tool. For fitness tracking in everyday life, heart rate, steps and sleep tracking are enough, and THEIA II has them.

Price against what you will use.

The best value is the watch whose features you will use; the best GPS watches on paper are not always the best value for your trips, and for running alone a Garmin Forerunner may be the better value. Compared with other watches here, expedition GPS watches add multi-day battery life and sapphire crystal you may not need on day trips, and an affordable watch without maps can be enough on marked trails. THEIA II costs CHF 369 or CHF 469, with maps, dual-frequency GPS, return to start and ABC sensors in 58 g. Its PVD and DLC finishes give it the look of a premium watch.

Hours with GPS on, from each maker.

Reviews of the best GPS watches use words like excellent battery life, impressive battery life, incredible battery life or exceptional battery life. Those words tell you less than the hours: excellent battery life for a day hike is not excellent battery life for a ten-day trek, and exceptional battery life in smartwatch use can still mean a short day with GPS on. Compare the same setting on all GPS watches you look at. Battery life with GPS on, from each maker:

• THEIA II: 15 h with GPS on; 20 days of battery life in normal use.
• Garmin Enduro 3: battery life up to 120 h with GPS, up to 320 h with solar charging.
• COROS VERTIX 2S: battery life of 118 h with GPS.
• Garmin Fenix 8 Solar: up to 67 h with GPS only on the 47 mm (92 h with solar), up to 95 h on the 51 mm (149 h with solar).
• Suunto Vertical 2: battery life up to 65 h in Performance mode with multi-band tracking; up to 250 h in Tour mode, with lower accuracy and heart rate off.
• COROS APEX 4, 46 mm: 53 h with all GNSS systems on; 65 h in its Endurance mode.
• Garmin Instinct 2 Solar: battery life up to 30 h with GPS, 48 h with solar.
• Apple Watch Ultra 4: up to 18 h of outdoor workout tracking, 45 h in Max Extended Workout.

Solar figures assume 50,000 lux of light the whole time. Multi-day battery life comes from solar charging or a bigger battery, and of these GPS watches the Garmin Enduro 3 gives the best battery life. If your trips last a day, GPS watches with a shorter battery life will do: check the hours against your longest day. Battery life figures: Garmin, COROS, Suunto and Apple product pages and manuals, Garmin Fenix 8 Solar from retailer listings, COROS APEX 4 from Tom’s Guide; checked 14 October 2026.

Water rating, buttons, knots.

On a boat, GPS watches show your position and speed and record your track; some GPS watches also record waypoints. Physical buttons on GPS watches make navigation easier in rain and spray or with gloves on, because water on a touchscreen can register as a touch. THEIA II locks its touchscreen during GPS tracking, you unlock it with the bottom button, and it shows speed in knots for sailing. Cold also shortens battery life, as with any lithium-ion battery, so keep the watch under your sleeve on winter tours. When you compare the best GPS watches for sailing, check the water rating: THEIA II is rated 10 ATM, and Polar and Suunto rate the Polar Grit X2 Pro and the Suunto Vertical 2 water resistant to 100 m.

What works with no signal.

Even the best GPS watches need a phone for some things. GPS tracking, maps you loaded before you left, the compass and the altimeter work on GPS watches without a phone. On THEIA II, maps, GPS tracking, return to start, the altimeter and the compass all work on the watch alone; only SOS needs your phone and a network. Notifications and syncing tracks to Strava go through the phone app. Before you take GPS watches into remote terrain, check which functions still work with no signal, and how much battery life they leave you.